When starting "Luvi" after driving at freeway speeds for an extended period of time she just doesen't seem to cooperate. After a couple attempts she will fire on a couple cylinders than I can gently coax her into running smoothly. We can again return to freeway speeds with no problem but the issue happens again after our next gas stop.
Cold start idle and performance is fine. Driving around town with frequent starts and stops and engine at normal operating temp everything is fine.
Starting issues just seem to happen after longer runs on warm days. Could vapor lock of some kind be the problem?
Difficulty starting warm engine.
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Briano1234
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Re: Difficulty starting warm engine.
What year of car, as it do make a difference.
If it is a 90-ish, then replace the CTS sensor as it is blue, and on the front of hte head, WARNING replace it on a cold block.
If it is a 80ish others will be along.
If it is a 90-ish, then replace the CTS sensor as it is blue, and on the front of hte head, WARNING replace it on a cold block.
If it is a 80ish others will be along.
Briano
Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click....
Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click....
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BandB
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Re: Difficulty starting warm engine.
Sorry I should have mentioned that "Luvi" is an 88 model...manual with A/C. Other than this issue she starts and runs fantastic..
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kamzcab86
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Re: Difficulty starting warm engine.
A few ideas:
- Fuel pump is overheating
- Starter is overheating (shouldn't be this since yours is a manual trans car, but...)
- Hot-start pulse relay is faulty
- Cold start valve is leaking
- Insufficient residual fuel pressure
- Air-flow sensor plate is out of adjustment
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BandB
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Re: Difficulty starting warm engine.
Thanks for the suggestions.
For further consideration. I did not have this problem prior to adjusting the O2 closed loop duty cycle to roughly 50%. It had been at 30%.
Wonder maybe..."if it ain't broke don't fix it" might apply here. I'll check all the parameters you suggested and report back. Will be a couple days though other priorities have arisen!!
For further consideration. I did not have this problem prior to adjusting the O2 closed loop duty cycle to roughly 50%. It had been at 30%.
Wonder maybe..."if it ain't broke don't fix it" might apply here. I'll check all the parameters you suggested and report back. Will be a couple days though other priorities have arisen!!
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gull
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Re: Difficulty starting warm engine.
Both of the CIS cars I've had did this after being shut off hot. I never figured out how to fix it. The workaround is to press the accelerator down partway, start the car, and hold the revs at 3000 or so until it smooths out. Usually takes 20-30 seconds. After that it idles.
My theory is this is some kind of vapor lock issue. I think the fuel in the injector lines boils due to heat soak and results in an incorrect mixture when the car is first started. That might be total BS, though; it's just a guess.
My theory is this is some kind of vapor lock issue. I think the fuel in the injector lines boils due to heat soak and results in an incorrect mixture when the car is first started. That might be total BS, though; it's just a guess.
VW fan who fell to the Honda side of the force
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Briano1234
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Re: Difficulty starting warm engine.
Well since the cheap bastards are putting more alcohol and methanol in the gas to reduce costs and make more monies.... I am sure that more bad gas is going to go around.gull wrote:Both of the CIS cars I've had did this after being shut off hot. I never figured out how to fix it. The workaround is to press the accelerator down partway, start the car, and hold the revs at 3000 or so until it smooths out. Usually takes 20-30 seconds. After that it idles.
My theory is this is some kind of vapor lock issue. I think the fuel in the injector lines boils due to heat soak and results in an incorrect mixture when the car is first started. That might be total BS, though; it's just a guess.
http://nhregister.com/articles/2011/06/ ... 269048.txt
Briano
Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click....
Yes as matter of fact, I have the Luck o'the Irish...everything I touch turns to fertilizer of the bovine variety.
You can lead a user to a link, but you can't make him Click....
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gull
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Re: Difficulty starting warm engine.
Pretty sure it's not bad gas in my case. It's been consistent for a long time.
If you have fuel pressure gauges, you might want to check the residual pressure. I've heard that a bad accumulator or check valve can exacerbate this, by letting the fuel pressure fall off after the car is shut down. Both parts are expensive enough and a big enough hassle to change that I wouldn't replace them without verifying there's a problem with them, though.
BTW, 30% duty cycle is a strong lean correction, indicating a pretty rich base mixture. Are you sure your control pressure regulator is operating properly?
If you have fuel pressure gauges, you might want to check the residual pressure. I've heard that a bad accumulator or check valve can exacerbate this, by letting the fuel pressure fall off after the car is shut down. Both parts are expensive enough and a big enough hassle to change that I wouldn't replace them without verifying there's a problem with them, though.
BTW, 30% duty cycle is a strong lean correction, indicating a pretty rich base mixture. Are you sure your control pressure regulator is operating properly?
VW fan who fell to the Honda side of the force
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BandB
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Re: Difficulty starting warm engine.
Thanks for all discussion. I had the chance to put some Freeway miles on Luvi and ran warm fuel pressure and fuel mixture tests. Fuel pressure both warm and residual were within spec. The fuel mixture duty cycle was up at 60%. I must have done something incorrectly when I first "adjusted" it.
Anyhow I've put a couple hundred miles on with a readjustment to 50% (and verified that it hasen't changed) and all is well. We have had some pretty warm days here in Colorado as of late so I'm quite confident the problem is fixed.
Again thanks to all for your assistance
Anyhow I've put a couple hundred miles on with a readjustment to 50% (and verified that it hasen't changed) and all is well. We have had some pretty warm days here in Colorado as of late so I'm quite confident the problem is fixed.
Again thanks to all for your assistance